1 /*
2 * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_MEMORY_ITERATOR_INLINE_HPP
26 #define SHARE_MEMORY_ITERATOR_INLINE_HPP
27
28 #include "classfile/classLoaderData.hpp"
29 #include "memory/iterator.hpp"
30 #include "oops/access.inline.hpp"
31 #include "oops/compressedOops.inline.hpp"
32 #include "oops/klass.hpp"
33 #include "oops/instanceKlass.inline.hpp"
34 #include "oops/instanceMirrorKlass.inline.hpp"
35 #include "oops/instanceClassLoaderKlass.inline.hpp"
36 #include "oops/instanceRefKlass.inline.hpp"
37 #include "oops/objArrayKlass.inline.hpp"
38 #include "oops/typeArrayKlass.inline.hpp"
39 #include "utilities/debug.hpp"
40
41 inline void MetadataVisitingOopIterateClosure::do_cld(ClassLoaderData* cld) {
42 cld->oops_do(this, ClassLoaderData::_claim_strong);
43 }
44
45 inline void MetadataVisitingOopIterateClosure::do_klass(Klass* k) {
46 ClassLoaderData* cld = k->class_loader_data();
47 MetadataVisitingOopIterateClosure::do_cld(cld);
48 }
49
50 #ifdef ASSERT
51 // This verification is applied to all visited oops.
52 // The closures can turn is off by overriding should_verify_oops().
53 template <typename T>
54 void OopIterateClosure::verify(T* p) {
55 if (should_verify_oops()) {
56 T heap_oop = RawAccess<>::oop_load(p);
57 if (!CompressedOops::is_null(heap_oop)) {
58 oop o = CompressedOops::decode_not_null(heap_oop);
59 assert(Universe::heap()->is_in(o),
60 "should be in closed *p " PTR_FORMAT " " PTR_FORMAT, p2i(p), p2i(o));
61 }
62 }
63 }
64 #endif
65
66 // Implementation of the non-virtual do_oop dispatch.
67 //
68 // The same implementation is used for do_metadata, do_klass, and do_cld.
69 //
70 // Preconditions:
71 // - Base has a pure virtual do_oop
72 // - Only one of the classes in the inheritance chain from OopClosureType to
73 // Base implements do_oop.
74 //
75 // Given the preconditions:
76 // - If &OopClosureType::do_oop is resolved to &Base::do_oop, then there is no
77 // implementation of do_oop between Base and OopClosureType. However, there
78 // must be one implementation in one of the subclasses of OopClosureType.
79 // In this case we take the virtual call.
80 //
81 // - Conversely, if &OopClosureType::do_oop is not resolved to &Base::do_oop,
82 // then we've found the one and only concrete implementation. In this case we
83 // take a non-virtual call.
84 //
85 // Because of this it's clear when we should call the virtual call and
86 // when the non-virtual call should be made.
87 //
88 // The way we find if &OopClosureType::do_oop is resolved to &Base::do_oop is to
89 // check if the resulting type of the class of a member-function pointer to
90 // &OopClosureType::do_oop is equal to the type of the class of a
91 // &Base::do_oop member-function pointer. Template parameter deduction is used
92 // to find these types, and then the IsSame trait is used to check if they are
93 // equal. Finally, SFINAE is used to select the appropriate implementation.
94 //
95 // Template parameters:
96 // T - narrowOop or oop
97 // Receiver - the resolved type of the class of the
98 // &OopClosureType::do_oop member-function pointer. That is,
99 // the klass with the do_oop member function.
100 // Base - klass with the pure virtual do_oop member function.
101 // OopClosureType - The dynamic closure type
102 //
103 // Parameters:
104 // closure - The closure to call
105 // p - The oop (or narrowOop) field to pass to the closure
106
107 template <typename T, typename Receiver, typename Base, typename OopClosureType>
108 static typename EnableIf<IsSame<Receiver, Base>::value, void>::type
109 call_do_oop(void (Receiver::*)(T*), void (Base::*)(T*), OopClosureType* closure, T* p) {
110 closure->do_oop(p);
111 }
112
113 template <typename T, typename Receiver, typename Base, typename OopClosureType>
114 static typename EnableIf<!IsSame<Receiver, Base>::value, void>::type
115 call_do_oop(void (Receiver::*)(T*), void (Base::*)(T*), OopClosureType* closure, T* p) {
116 // Sanity check
117 STATIC_ASSERT((!IsSame<OopClosureType, OopIterateClosure>::value));
118 closure->OopClosureType::do_oop(p);
119 }
120
121 template <typename OopClosureType, typename T>
122 inline void Devirtualizer::do_oop_no_verify(OopClosureType* closure, T* p) {
123 call_do_oop<T>(&OopClosureType::do_oop, &OopClosure::do_oop, closure, p);
124 }
125
126 template <typename OopClosureType, typename T>
127 inline void Devirtualizer::do_oop(OopClosureType* closure, T* p) {
128 debug_only(closure->verify(p));
129
130 do_oop_no_verify(closure, p);
131 }
132
133 // Implementation of the non-virtual do_metadata dispatch.
134
135 template <typename Receiver, typename Base, typename OopClosureType>
136 static typename EnableIf<IsSame<Receiver, Base>::value, bool>::type
137 call_do_metadata(bool (Receiver::*)(), bool (Base::*)(), OopClosureType* closure) {
138 return closure->do_metadata();
139 }
140
141 template <typename Receiver, typename Base, typename OopClosureType>
142 static typename EnableIf<!IsSame<Receiver, Base>::value, bool>::type
143 call_do_metadata(bool (Receiver::*)(), bool (Base::*)(), OopClosureType* closure) {
144 return closure->OopClosureType::do_metadata();
145 }
146
147 template <typename OopClosureType>
148 inline bool Devirtualizer::do_metadata(OopClosureType* closure) {
149 return call_do_metadata(&OopClosureType::do_metadata, &OopIterateClosure::do_metadata, closure);
150 }
151
152 // Implementation of the non-virtual do_klass dispatch.
153
154 template <typename Receiver, typename Base, typename OopClosureType>
155 static typename EnableIf<IsSame<Receiver, Base>::value, void>::type
156 call_do_klass(void (Receiver::*)(Klass*), void (Base::*)(Klass*), OopClosureType* closure, Klass* k) {
157 closure->do_klass(k);
158 }
159
160 template <typename Receiver, typename Base, typename OopClosureType>
161 static typename EnableIf<!IsSame<Receiver, Base>::value, void>::type
162 call_do_klass(void (Receiver::*)(Klass*), void (Base::*)(Klass*), OopClosureType* closure, Klass* k) {
163 closure->OopClosureType::do_klass(k);
164 }
165
166 template <typename OopClosureType>
167 inline void Devirtualizer::do_klass(OopClosureType* closure, Klass* k) {
168 call_do_klass(&OopClosureType::do_klass, &OopIterateClosure::do_klass, closure, k);
169 }
170
171 // Implementation of the non-virtual do_cld dispatch.
172
173 template <typename Receiver, typename Base, typename OopClosureType>
174 static typename EnableIf<IsSame<Receiver, Base>::value, void>::type
175 call_do_cld(void (Receiver::*)(ClassLoaderData*), void (Base::*)(ClassLoaderData*), OopClosureType* closure, ClassLoaderData* cld) {
176 closure->do_cld(cld);
177 }
178
179 template <typename Receiver, typename Base, typename OopClosureType>
180 static typename EnableIf<!IsSame<Receiver, Base>::value, void>::type
181 call_do_cld(void (Receiver::*)(ClassLoaderData*), void (Base::*)(ClassLoaderData*), OopClosureType* closure, ClassLoaderData* cld) {
182 closure->OopClosureType::do_cld(cld);
183 }
184
185 template <typename OopClosureType>
186 void Devirtualizer::do_cld(OopClosureType* closure, ClassLoaderData* cld) {
187 call_do_cld(&OopClosureType::do_cld, &OopIterateClosure::do_cld, closure, cld);
188 }
189
190 // Dispatch table implementation for *Klass::oop_oop_iterate
191 //
192 // It allows for a single call to do a multi-dispatch to an optimized version
193 // of oop_oop_iterate that statically know all these types:
194 // - OopClosureType : static type give at call site
195 // - Klass* : dynamic to static type through Klass::id() -> table index
196 // - UseCompressedOops : dynamic to static value determined once
197 //
198 // when users call obj->oop_iterate(&cl).
199 //
200 // oopDesc::oop_iterate() calls OopOopIterateDispatch::function(klass)(cl, obj, klass),
201 // which dispatches to an optimized version of
202 // [Instance, ObjArry, etc]Klass::oop_oop_iterate(oop, OopClosureType)
203 //
204 // OopClosureType :
205 // If OopClosureType has an implementation of do_oop (and do_metadata et.al.),
206 // then the static type of OopClosureType will be used to allow inlining of
207 // do_oop (even though do_oop is virtual). Otherwise, a virtual call will be
208 // used when calling do_oop.
209 //
210 // Klass* :
211 // A table mapping from *Klass::ID to function is setup. This happens once
212 // when the program starts, when the static _table instance is initialized for
213 // the OopOopIterateDispatch specialized with the OopClosureType.
214 //
215 // UseCompressedOops :
216 // Initially the table is populated with an init function, and not the actual
217 // oop_oop_iterate function. This is done, so that the first time we dispatch
218 // through the init function we check what the value of UseCompressedOops
219 // became, and use that to determine if we should install an optimized
220 // narrowOop version or optimized oop version of oop_oop_iterate. The appropriate
221 // oop_oop_iterate function replaces the init function in the table, and
222 // succeeding calls will jump directly to oop_oop_iterate.
223
224
225 template <typename OopClosureType>
226 class OopOopIterateDispatch : public AllStatic {
227 private:
228 class Table {
229 private:
230 template <typename KlassType, typename T>
231 static void oop_oop_iterate(OopClosureType* cl, oop obj, Klass* k) {
232 ((KlassType*)k)->KlassType::template oop_oop_iterate<T>(obj, cl);
233 }
234
235 template <typename KlassType>
236 static void init(OopClosureType* cl, oop obj, Klass* k) {
237 OopOopIterateDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
238 }
239
240 template <typename KlassType>
241 void set_init_function() {
242 _function[KlassType::ID] = &init<KlassType>;
243 }
244
245 template <typename KlassType>
246 void set_resolve_function() {
247 // Size requirement to prevent word tearing
248 // when functions pointers are updated.
249 STATIC_ASSERT(sizeof(_function[0]) == sizeof(void*));
250 if (UseCompressedOops) {
251 _function[KlassType::ID] = &oop_oop_iterate<KlassType, narrowOop>;
252 } else {
253 _function[KlassType::ID] = &oop_oop_iterate<KlassType, oop>;
254 }
255 }
256
257 template <typename KlassType>
258 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
259 set_resolve_function<KlassType>();
260 _function[KlassType::ID](cl, obj, k);
261 }
262
263 public:
264 void (*_function[KLASS_ID_COUNT])(OopClosureType*, oop, Klass*);
265
266 Table(){
267 set_init_function<InstanceKlass>();
268 set_init_function<InstanceRefKlass>();
269 set_init_function<InstanceMirrorKlass>();
270 set_init_function<InstanceClassLoaderKlass>();
271 set_init_function<ObjArrayKlass>();
272 set_init_function<TypeArrayKlass>();
273 }
274 };
275
276 static Table _table;
277 public:
278
279 static void (*function(Klass* klass))(OopClosureType*, oop, Klass*) {
280 return _table._function[klass->id()];
281 }
282 };
283
284 template <typename OopClosureType>
285 typename OopOopIterateDispatch<OopClosureType>::Table OopOopIterateDispatch<OopClosureType>::_table;
286
287
288 template <typename OopClosureType>
289 class OopOopIterateBoundedDispatch {
290 private:
291 class Table {
292 private:
293 template <typename KlassType, typename T>
294 static void oop_oop_iterate_bounded(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
295 ((KlassType*)k)->KlassType::template oop_oop_iterate_bounded<T>(obj, cl, mr);
296 }
297
298 template <typename KlassType>
299 static void init(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
300 OopOopIterateBoundedDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k, mr);
301 }
302
303 template <typename KlassType>
304 void set_init_function() {
305 _function[KlassType::ID] = &init<KlassType>;
306 }
307
308 template <typename KlassType>
309 void set_resolve_function() {
310 if (UseCompressedOops) {
311 _function[KlassType::ID] = &oop_oop_iterate_bounded<KlassType, narrowOop>;
312 } else {
313 _function[KlassType::ID] = &oop_oop_iterate_bounded<KlassType, oop>;
314 }
315 }
316
317 template <typename KlassType>
318 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k, MemRegion mr) {
319 set_resolve_function<KlassType>();
320 _function[KlassType::ID](cl, obj, k, mr);
321 }
322
323 public:
324 void (*_function[KLASS_ID_COUNT])(OopClosureType*, oop, Klass*, MemRegion);
325
326 Table(){
327 set_init_function<InstanceKlass>();
328 set_init_function<InstanceRefKlass>();
329 set_init_function<InstanceMirrorKlass>();
330 set_init_function<InstanceClassLoaderKlass>();
331 set_init_function<ObjArrayKlass>();
332 set_init_function<TypeArrayKlass>();
333 }
334 };
335
336 static Table _table;
337 public:
338
339 static void (*function(Klass* klass))(OopClosureType*, oop, Klass*, MemRegion) {
340 return _table._function[klass->id()];
341 }
342 };
343
344 template <typename OopClosureType>
345 typename OopOopIterateBoundedDispatch<OopClosureType>::Table OopOopIterateBoundedDispatch<OopClosureType>::_table;
346
347
348 template <typename OopClosureType>
349 class OopOopIterateBackwardsDispatch {
350 private:
351 class Table {
352 private:
353 template <typename KlassType, typename T>
354 static void oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* k) {
355 ((KlassType*)k)->KlassType::template oop_oop_iterate_reverse<T>(obj, cl);
356 }
357
358 template <typename KlassType>
359 static void init(OopClosureType* cl, oop obj, Klass* k) {
360 OopOopIterateBackwardsDispatch<OopClosureType>::_table.set_resolve_function_and_execute<KlassType>(cl, obj, k);
361 }
362
363 template <typename KlassType>
364 void set_init_function() {
365 _function[KlassType::ID] = &init<KlassType>;
366 }
367
368 template <typename KlassType>
369 void set_resolve_function() {
370 if (UseCompressedOops) {
371 _function[KlassType::ID] = &oop_oop_iterate_backwards<KlassType, narrowOop>;
372 } else {
373 _function[KlassType::ID] = &oop_oop_iterate_backwards<KlassType, oop>;
374 }
375 }
376
377 template <typename KlassType>
378 void set_resolve_function_and_execute(OopClosureType* cl, oop obj, Klass* k) {
379 set_resolve_function<KlassType>();
380 _function[KlassType::ID](cl, obj, k);
381 }
382
383 public:
384 void (*_function[KLASS_ID_COUNT])(OopClosureType*, oop, Klass*);
385
386 Table(){
387 set_init_function<InstanceKlass>();
388 set_init_function<InstanceRefKlass>();
389 set_init_function<InstanceMirrorKlass>();
390 set_init_function<InstanceClassLoaderKlass>();
391 set_init_function<ObjArrayKlass>();
392 set_init_function<TypeArrayKlass>();
393 }
394 };
395
396 static Table _table;
397 public:
398
399 static void (*function(Klass* klass))(OopClosureType*, oop, Klass*) {
400 return _table._function[klass->id()];
401 }
402 };
403
404 template <typename OopClosureType>
405 typename OopOopIterateBackwardsDispatch<OopClosureType>::Table OopOopIterateBackwardsDispatch<OopClosureType>::_table;
406
407
408 template <typename OopClosureType>
409 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass) {
410 OopOopIterateDispatch<OopClosureType>::function(klass)(cl, obj, klass);
411 }
412
413 template <typename OopClosureType>
414 void OopIteratorClosureDispatch::oop_oop_iterate(OopClosureType* cl, oop obj, Klass* klass, MemRegion mr) {
415 OopOopIterateBoundedDispatch<OopClosureType>::function(klass)(cl, obj, klass, mr);
416 }
417
418 template <typename OopClosureType>
419 void OopIteratorClosureDispatch::oop_oop_iterate_backwards(OopClosureType* cl, oop obj, Klass* klass) {
420 OopOopIterateBackwardsDispatch<OopClosureType>::function(klass)(cl, obj, klass);
421 }
422
423 #endif // SHARE_MEMORY_ITERATOR_INLINE_HPP